Investigations related to morphine's addictive properties are planned. Experiments concerning morphine's neuroanatomical site(s) of action(s), the neuropharmacological basis of morphine's action(s) and the long-term consequences of in utero exposure to morphine are designed. A correlative approach involving both neurochemical and behavioral procedures will be employed in all experiments. Behavioral procedures will include methods of intravenous self-administration, physical dependence and analgesia. Neurochemical procedures will include methods for measuring levels of catecholamines and their metabolites in discrete regions of the brain. The possible role of other agents (e.g. amphetamines) in predisposing to morphine addiction will also be investigated.